Roof bolting method and assembly

ABSTRACT

A roof bolting drill assembly for use with a mining machine which assembly is selectively mountable and demountably from the mining machine. Cooperable means are included on the mining machine and roof bolting assembly whereby the assembly is clamped to the mining machines for only linear motion for repositioning and unclamped from the mining machine during a bolting operation to permit limited relative traverse motion of the mining machine for simultaneous mining. A method of utilizing the above structure to carry out a simultaneous mining and roof bolting operation is also disclosed.

United States Patent Kacmarcy Mar. 7, 1972 [54] ROOF BOLTING METHOD ANDASSEMBLY [72] inventor: Charles W. Kacmarey, PO. Box 262,

Franklin, Pa. 16323 [22] Filed: Jan. 7, 1970 [21 Appl.No.: 1,530

Related U.S. Application Data [63] Continuation of Ser. No. 777,313,Nov. 20, 1968,

abandoned.

[52] U.S.Cl ..299/11, 173/23, 173/46, 173/52 [51] Int. Cl. ..E2lc 11/02[58] Field of Search ..299/l8, 11, 33; 173/23, 24, 173/34, 35, 29, 46;175/315; 61/45 [56] References Cited UNlTED STATES PATENTS 2,904,3199/1959 Newton ..299/33 3,199,611 8/1965 Densmore 173/24 3,268,258 8/1966Kegel ..299/l8 3,493,058 2/1970 Zitko 173/23 Primary Examiner-Ernest R.Purser AtlorneyE. Wallace Breisch [5 7] ABSTRACT A roof bolting drillassembly for use with a mining machine which assembly is selectivelymountable and demountably from the mining machine. Cooperable means areincluded on the mining machine and roof bolting assembly whereby theassembly is clamped to the mining machines for only linear motion forrepositioning and unclamped from the mining machine during a boltingoperation to permit limited relative traverse motion of the miningmachine for simultaneous mining. A method of utilizing the abovestructure to carry out a simultaneous mining and roof bolting operationis also disclosed.

15 Claims, 9 Drawing Figures PATENTEDMAR 7 I972 SHEET 1 OF 5 INVENTORCHARLES n. KACMARCY PATENTEDMAR '7 I972 3. 647, 262

SHEET 2 [IF 5 INVENTOR.

CHARL E5 m KACMARW PATENTEDMA R 1 1912 sum 3 OF 5 INVENTOR.

CHARLES H. KACMARCY PATENTEDMAR 1 m2 SHEET U [1F 5 INVENTOR.

CHARLES m KACMARCV PATENTEDMAR 7 I972 3. 647-, 262

sum 5 OF 5 INVENTOR.

CHARLES W K461449627 ROOF BOLTING METHOD AND ASSEMBLY This applicationis a continuation of application Ser. No. 777,313, filed Nov. 20, 1968and now abandoned.

Roof conditions in some mines necessitate roof bolting because certainrock strata forming the roof of the mine are not capable of supportingtheir own weight after the removal of the mineral thereunder. By the useof the present invention, means required for such roof bolting arecarried by a forwardly advancing mining machine to the desired roofbolting location and detached therefrom. The roof bolting operation canthen be accomplished while the mining machine continues mining forwardlythereof. After such roof bolting is accomplished, the apparatus ishydraulically reattached to the mining machine and brought forwardlytowards the mining end thereof.

With a roof bolting apparatus of this invention the bolting operationcan proceed without interrupting the mining operation; there is no needto be confined to a miner of the ripper bar type for the mining machinecan move forward without interferring with the roof bolting operation;conveying the roof bolting apparatus by means of a mining machine helpsto insure an operators safety and speed production; the forwardlyadvancing mining machine can move laterally within predetermined limitswithout affecting the roof bolting operation; and no mining personnelneed be exposed to the risk of working under an unsupported roof.

These and other objects and advantages of this invention will be morereadily apparent from a reading of the following detailed descriptionand drawing in which:

' FIG. 1 is a schematic representation of a mining machine provided withthe semisatellite roof bolting apparatus of this invention;

FIG. 2 is a side view of the roof bolting apparatus of this inventionmounted in position on a mining machine;

FIG. 3 is an elevational view of the roof bolting apparatus shown inFIG. 2;

FIG. 4 is a cross-sectional view taken on lines 4--4 of FIG. 2 andshowing, primarily, a way clamp hinge assembly;

FIG. 5 is an end view of a portion of the hinge assembly shown in FIG.4;

FIG. 6 is a cross-sectional view taken on lines 6-6 of FIG. 2 showing,primarily, a way clamp cylinder assembly;

FIG. 7 is an end view of the way clamp cylinder assembly of FIG. 6;

FIG. 8 is a cross-sectional view taken on lines 8-8 of FIG. 2 showing,primarily, a traverse drive mechanism; and

FIG. 9 is a partial cross-sectional taken on lines 9-9 of FIG. 2showing, primarily, a traverse drive idler.

Referring to FIG. 1, a mining machine 14 is supported in any suitablemanner, and rendered movable over a floor 16 by a pair of well-knownendless circulating crawler tracks 18. Crawler track cover plates 20 arefixed to the crawler frame of machine 14 at the lateral sides thereofand a roof bolt assembly of this invention, generally indicated at 22,is secured to such plates 20. As hereinafter described in detailassembly 22 is capable of being selectively mounted or associated anddismounted or disassociated from machine 14. These terms as hereinbelowused shall refer to a relationship between assembly 22 and machine 14whereby: associated designates a supported condition of assembly 22wherein assembly 22 is completely supported by machine 14 and a slidingrelationship exists between machine 14 and assembly 22; anddisassociated designates a supported condition of assembly 22 whereinassembly 22 is self-supported (i.e., machine 14 has no portion thereofin supporting contact with assembly 22) and a loose guiding relationshipexists between machine 14 and assembly 22.

Roof bolt assembly 22 includes a plurality of components which allowsuch assembly 22 to be selectively captively disassociated from machine14 when it is desired to place a roof bolt support in a roof of a minepassageway while still continuing the forward advance of machine 14.Such components of the roof bolt assembly 22 are affixed to an elongatedpanel plate 24 which in turn is secured to the track cover plates 20 bymeans of a pair of elongated V-jaw rail clamps 26 which traverse themajor extent of panel plate 24 and are hingedly connected thereto at theupper and lower sides thereof. As hereinafter described in detail,clamps 26 are selectively clamped or associated to a pair of V-rails 28,which traverse the major extent of cover plates 20 and are rigidlyaffixed thereto at the upper and lower sides thereof, such that machine14 carries assembly 22 therewith during a forward movement thereof andprovides a sliding relationship therebetween as hereinafter described,or, unclamped or disassociated from rails 28 an amount for which rails28 provide a guiding relationship with clamps 26. As shown clamps 26have concave surfaces which interfit with and partially encompassreciprocal convex surfaces of rails 28. The sliding relationship betweenrails 28 and clamps 26 hereinabove described allows substantially onlylinear motion of assembly 22 with respect to machine 14 and the guidingrelationship thereof allows limited relative transverse motion betweenassembly 22 and machine 14 as hereinafter described.

The components of assembly 22 hereinabove mentioned which allow theselective association and disassociation of assembly 22 from miningmachine 14 include: a hydraulically operated ceiling jack 30 and ahydraulically operated floor jack 31 which are secured to panel plate 24intermediate the axial ends thereof; and a hydraulically operatedelongated jaw clamp cylinder 32 (FIGS. 6 and 7) which is locatedintermediate the axial ends of clamps 26, extends perpendicular toclamps 26 and is hingedly connected thereto by hinge means 34 (FIG. 6)which, hinge means 34, comprise lug portions 36 which extend outwardlyfrom clamp 26 and removable pins 38 which hingedly secures portions 36to the axial ends of cylinder 32.

The clamps 26 are hingedly secured to assembly 22 adjacent thelongitudinal ends thereof by hinge means 40 and 42 which secure,respectively, the upper and lower clamps 26 (FIG. 4), to the upper andlower portions of panel plate 24. Hinge means 40 and 42 comprise: a lugportion 44 which is rigidly secured to panel plate 24 and extendsoutwardly therefrom (outwardly being defined as away from machine 14);and a swivel plate 46 which is hingedly connected to lug 44 adjacent theoutermost end thereof by a removable pin 48 and extends inwardlytherefrom to an innermost end thereof which is rigidly secured to aclamp 26.

By means of the components set forth hereinabove the assembly 22 can bedisassociated and associated from the mining machine 14 by selectivelysupplying, from any suitable source, hydraulic pressure fluid initiallyto either the jaw clamp cylinder 32 or the ceiling and floor jacks 30and 31, respectively. To accomplish such disassociation of an assembly22 which is presently associated (or clamped in a carrying position) tomachine 14, hydraulic fluid is initially supplied to the ceiling jack 30and floor jack 31, thereby causing piston rods 58 and 60 respectively,to extend, respectively, toward the roof 62 and floor 16 of the minepassageway. When the free ends of rods 58 and 60 respectively contactroof 62 and floor 16, the pressure fluid will continue to build up apressure within jacks 30 and 31 until such pressure reaches apredetermined value which can hold assembly 22 in a stationary oranchored position without any dependency upon V-rails 28 and clamps 26.When such a predetermined pressure value is obtained, a pressureoperated sequence valve (not shown), which is of any suitableconstruction and is positioned in a pressure fluid line extendingbetween the jacks 30 and 31 and jaw clamp cylinder 32, is automaticallyopened thereby permitting pressure fluid to flow to the head end of jawclamp cylinder 32. Such pressure fluid causes a piston rod 64 ofcylinder 32 to extend upwardly, thereby, because of the particularconfiguration of hinge means 34, 40 and 42 hereinabove described,releases the assembly 22 from any direct association with machine 14.The vertical movement of clamps 26 is limited by upper and lower stopplates 66 and 68 respectively, which are firmly affixed to panel plate24 on the inner side thereof, (inner being defined as that side closestto the mining machine). Plates 66 and 68 are positioned verticallyadjacent clamps 26 at a predetermined distance therefrom to restrict thevertical movement of clamps 26 to an amount which will permit clamps 26to clearly disassociated from rails 28 while still permitting a looseguiding relationship between clamps 26 and rails 28. In other words, ifthe mining machine 14 varies in either a transverse or verticaldirection a distance greater than the clearance between clamps 26 andrails 28, contact therebetween will result. The maximum distance betweenthe clamps 26 must be less than the overall distance between the rails28 in order to maintain the guiding relationship between clamps 26 andrails 28 hereinbefore described. At least one roof bolt assembly iswithin sight of the miner operator as he maneuvers the machine 14 to cutcoal and any such contact between clamps 26 and rails 28 can bealleviatedby the operator stopping operations or maneuvering the machine14. Additional safeguards can be provided to reduce the chance of acontact between clamps 26 and rails 28 causing damage to the machine 14or assembly 22, for example: a pressure relief valve in the pressurefluid lines between the ceiling jack 30 and floor jack 31 which willopen when an excessive amount of pressure is applied to the respectiverods 58 and 60, thereby allowing the retraction of one of the rods withan equivalent extension of the other; and springs 116 and 114 at therespective ends of jacks 30 and 31 which allow a movement of such jacksrelative to the assembly22.

After the disassociation of assembly 22 from mining machine 14, machine14 can advance straight forwardly without regard to obstructing a roofbolting operation hereinbelow described. The forward advance of machine14 from the point of assembly 22 disassociation therefrom is limited bythat distance between such point and the end of the V-rail 28 rearwardthereof. The time required to mine such distance is normally sufficientto complete a roof bolting operation.

A roof-bolting drill assembly 72 is firmly affixed, in any suitablemanner, to panel plate 24 forwardly of jacks 30 and 31. Assembly 72 isof any suitable type known in the art and as shown includes: a drillingtool 74 which is guided at the upper end thereof by a drill-centeringguide 76 and is secured at the lower end thereof by a drill chuck 78; afluid-operated drill motor 80 which rotationally drives tool 74 bysupplying power therefrom, through a drill gearbox 82 to the drill chuck78; and a fluid-operated drill feed cylinder 84 which verticallyadvances tool 74 during a drilling operation. Another operationaccomplished by the roof-bolting drill assembly 72 is the operation ofrotating and tightening the roof bolts (such operation being known aswrenching). For further description of the operation and construction ofsuch a roof-bolting drill reference is made to US. Pat. No. 2,741,461.

With such a unit 72, a well-known roof bolting operation is accomplishedduring the time assembly 22 is disassociated from machine 14 ashereinbefore described. In addition to unit 72, assembly 22 has awell-known timber cylinder 86 affixed thereto inward of tool 74 and in asimilar transverse plane therewith. With such a cylinder 86, a rooftimber (not shown) may be supported against the passageway roof 62 priorto the drilling period. After the placement of a roof timber thedrilling and insertion of a roof bolt can proceed through such timberdirectly into roof 62.

After the completion of the roof drilling operation the assembly 22 isclamped or associated with the machine 14. To accomplish suchassociation of an assembly 22, hydraulic fluid is supplied to the rodend of jaw clamp cylinder 32 to cause rod 64 to descend downwardly untilclamps 26 contact rail 28 an amount sufficient to result in rails 28being capable of independently supporting assembly 22 while maintaininga sliding relationship between rails 28 and clamps 26. Such arelationship is assured by means of preset jackscrews 88 which extendbetween hinge means 34. When clamps 26 are sufiiciently secured to rails28 a pressure-operated sequence valve (not shown), which is of anysuitable construction and is positioned in a pressure fluid lineextending between the jacks 30 and 31 and jaw clamp cylinder 32, isautomatically opened thereby permitting pressure fluid flow to jacks 30and 31. The flowing pressure fluid causes the pistons 58 and 60 towithdraw, respectively, downward and upward from the roof 62 and floor16 of the mine passageway. Such a withdrawal of pistons 58 and 60results in assembly 22 being completely supported on mining machine 14,thereby enabling machine 14 to carry assembly 22 therewith through aforward or rearward movement thereof.

The association of assembly 22 to mining machine 14 as hereinabovedescribed occurs adjacent the rearward end of the rails 28 because ofthe forward advance of machine 14 with respect to the disassociatedassembly 22 during the roof bolting operation thereof. It is possible tomake such initial association adjacent the forward endof the machine 14by moving the machine 14 rearwardly while assembly 22 is disassociatedtherefrom and then associating assembly 22 to machine 14 when theforward end thereof comes in proximity of assembly 22. Such a rearwardmovement of mining machine 14 would decrease the operation capabilitiesof machine 14 therefore assembly 22 of this invention is provided with atraverse drive means for moving an associated assembly 22 from therearward end of machine 14 forwardly to the forward end thereof withoutinterferring and simultaneously with the forward advance of machine 14.

The traverse drive means may be of any suitable construction and asshown include a traverse drive sprocket which is located intermediatethe upper and lower V-rails 28 adjacent the inner side of panel plate 24and intermediate the rear hinges 40 and 42 and jacks 30 and 31. Sprocket100 will move assembly 22 axially with respect to machine 14 by means ofengagement of the teeth of sprocket 100 with an axially extendingtraverse chain 92. Chain 92 is located intermediate the upper and lowerV-rails 28 adjacent the inner side of panel plate 24 and has the endsthereof secured to suitable chain-connecting means 98, which means 98are secured to chain anchor posts 94 and 96 which are located,respectively, adjacent the forward and rearward ends of rails 28 andwhich extend between the upper and lower rails 28 and are firmly securedthereto.

Sprocket 100 is powered in any suitable manner and as shown afluid-operated motor 102 which has the power output thereof transferredthrough a suitable gearing arrangement generally indicated at 102, to adrive shaft 104 which rotationally drives sprocket 100. Motor 102 issecured to panel plate 24 at the outer side thereof. Shaft 104 extendstransversely of machine 14 through plate 24 to sprocket 100.

To insure proper engagement of teeth of sprocket 100 with the links ofchain 92 a well-known idler sprocket 106 is rotatably affixed to thepanel plate 22 rearwardly adjacent sprocket 100. With such a well-knownarrangement of idler sprocket 106 with drive sprocket 100, proper toothand link engagement is assured by passing chain 92 under idler sprocket106 and up and over sprocket 100.

With the traverse drive arrangement hereinabove described an associatedassembly 22 can be brought to the forward end of machine 14 from anassociated position rearwardly thereof by supplying power from motor 102which is sufficient to overcome the frictional resistance which existsbetween the inner surfaces of jaw clamps 26 and the outer surfaces ofrails 28 when assembly 22 is in an associated position with respect tomachine 14. After overcoming such frictional resistance, assembly 22will slide forwardly with respect to stationary rails 28, therebycreating wear between the sliding surfaces of clamps 26 and rail 28. Toprevent the wear from causing premature failure or replacement of rails28, wear plates 108 are affixed on the contact surfaces thereof.

Forward and rearward plow plates 100 and 112, respectively, extenddiagonally outwardly from panel plate 22 and having the inner endsthereof firmly secured to respective axial ends of plate 22 and have theouter ends thereof form a tieback, in any suitable manner, to plate 22intermediate the axial ends thereof. Plow plates 110 and 112 are adesirable integral part of assembly 22 because the forward and rearwardadvance of machine 14 and assembly 22 might necessitate displacement ofmined mineral which has accumulated at the sides of the minedpassageway. The diagonal configuration of plates 110 and 112 will easethe burden of creating such displacement, and will, additionally,protect parts of assembly 22 which would otherwise been exposed todamage from such mined mineral.

A suitable control means is provided which will allow an operator toselectively provide pressure fluid to the traverse motor 102, thesealing and floor jacks 30 and 31, the timber cylinder 86, the drillfeed cylinder 84 and the drill motor 80. As shown such control meanscomprises a control panel 114 secured to plate 24 adjacent the upperrearward end thereof which contains a plurality of independent controls115 to allow the selective operations hereinabove mentioned. Pressurefluid to panel 114 may be provided from any suitable external source,either a pressure fluid line to assembly 22 from machine 14 or apressure fluid line to assembly 22 completely independent of machine 14.By having the control panel 14 an integral part of assembly 22 thenumber of traveling fluid pressure lines can be limited to one.

Although a singular assembly 22 which is associated and disassociatedfrom machine 14 at one side thereof is hereinabove discussed, it is tobe understood that the optimum operation of this invention contemplatesthe use of an assembly 22 being placed on either side of the forwardlyadvancing mining machine 14 (see FIG. 1).

Some significant functions of this invention are the ability of assembly22 to disassociate from machine 14 and place a roof bolt in a passagewayroof while the machine 14 continues to mine mineral forwardly thereofand the ability of assembly 22 to associate with machine 14 at therearward end thereof and be traversed from such point of association tothe forward end of machine 14. By following the principles taught bythis invention, one skilled in the art can achieve the hereinabovementioned functions with structural alterations to the preferredembodiment hereinbefore described, for example: ceiling and floor jacks30 and 31, respectively, do not have to be in axial alignment with oneanother; configurations other than a "V for clamps 26 and rails 28 canbe provided; the respective concave and convex surfaces of clamps 26 andrails 28 can be reversed, for example, rails 28 can have concavesurfaces which interfit with and partially encompass reciprocal convexsurfaces of clamps 26; drill motor 80 can be electronically poweredrather than by pressure fluid; timber cylinder 86 can be totallyeliminated from assembly 22 if there is no need for timber roofsupports; and the like.

The description herein does not limit the structure of this inventionand the invention is defined by the scope of the claims set forthhereinafter.

What is claimed is:

l. A roof bolting method comprising: transporting in a given directionby mobile means a drill assembly within an underground passageway withsaid drill assembly being means, moving said drill assembly in saidgiven direction to selectively reposition said drill assembly withrespect to said mobile means.

3. A method as specified in claim 1 including the additional steps'of:during said releasing said drill assembly from said support means,locating said mobile means to maintain limited relative linear andtransverse motions between said drill assembly and said support means;and subsequent to said retracting said relatively movable means, movingsaid drill assembly in said given direction to selectively repositionsaid drill assembly with respect to said mobile means.

4. A method as specified in claim 3 including the additional step of:during said drilling maintaining said limited relative linear andtransverse motions.

5. A method as specified in claim 4 wherein said drill assemblyadditionally includes selectively extendable and retractable relativelymovable timber jack means and comprising the additional steps of:subsequent to said anchoring of said drill assembly and prior to saiddrilling, anchoring a timber roof support intermediate said roof supportand said timber jack means by extending jack means into engagement withsaid timber roof support and continuing said extending until said timberroof support engages said roof surface and said anchoring is complete;and prior to said moving said drill assembly, retracting said timberjack means until said timber jack means are free from said timber roofsupport.

6. A method as specified in claim 5 wherein said drilling is in saidroof surface above said timber jack support and including the additionalstep of; subsequent to said drilling and prior to said retracting saidtimber assembly, securing said timber jack support said roof surface byroof anchoring means extending between said timer assembly and said roofbolt hole.

7. A method as specified in claim 4 including the additional step of:prior to said moving said drill assembly, securing a roof anchoringmeans in said roof bolt hole.

8. A drilling apparatus comprising: an elongated mobile assembly; atleast one drill assembly; cooperable means carried by said drillassembly and said mobile assembly for releasably securing said drillassembly to said mobile assembly; said cooperable means including anelongated portion carried by releasably secured to support means carriedby said mobile means during said transporting by selective clamping andunclamping said drill assembly from said support means and with saiddrill assembly having selective extendable and retractable relativelymovable portions; initiating anchoring of said drill assembly betweenthe roof and floor surfaces of said underground passageway by extendingsaid relatively movable portions into engagement with said roof andfloor surfaces, respectively; completing said anchoring andsubstantially simultaneously therewith unclamping said drill assemblyfrom said support means; drilling at least one roof bolt hole above saidroof surface; clamping said drill assembly to said support means withlimited motion only in said given direction being maintained betweensaid drill assembly and said mobile means; and retracting saidrelatively movable means until said relatively movable means are freefrom said roof and floor surfaces.

2. A method as specified in claim 1 including the additional step of:subsequent to said retracting said relatively movable one of saidassemblies and a clamping portion carried by the other of saidassemblies with said clamping portion being selectively verticallymovable into a clamped and unclamped relationship with said supportportion; said drill assembly having selectively extendable andretractable anchoring means relatively movable along a vertical axis;and control means carried by at least one said assemblies forselectively actuating said cooperable means and said anchoring means.

9. A drilling apparatus as specified in claim 8 wherein said drillassembly additionally comprises a selectively extensible roof supporttimber jack.

10. A drilling apparatus as specified in claim 8 with said clampingportion being locatable with respect to said support portion to providelimited relative linear and transverse motions between said clampingportion and said support portion when said clamping portion is inunclamped relationship with said support portion; and limitedrelativemotion only in the elongated direction of said mobile assemblybetween the clamping portion and said support portion when said clampingportion is in clamped relationship with said support portion.

11. A drilling apparatus as specified in claim 10 with one of saidportions having a pair of continuous vertically concaved oppositelyfacing surfaces which interfit with and at least partially encompass apair of continuous vertically convex surfaces on the other of saidportions.

12. A drilling apparatus as specified in claim 11 wherein said supportportion is fixedly secured to said mobile assembly and said clampingportion is pivotally secured to said drill assembly.

13. A drilling apparatus as specified in claim 12 wherein said concavesurfaces are surfaces of said clamping portion and said convex surfacesare surfaces of said support portion.

14. A drilling apparatus as specified in claim 8 additionally includingpositioning means carried by at least one of said assemblies forselectively positioning said drill assembly with respect to said mobileassembly.

15. A drilling apparatus as specified in claim 14 additionally includingcontrol means carried by at least one of said assemblies for selectivelyactuating said positioning means.

1. A roof bolting method comprising: transporting in a given directionby mobile means a drill assembly within an underground passageway withsaid drill assembly being releasably secured to support means carried bysaid mobile means during said transporting by selective clamping andunclamping said drill assembly from said support means and with saiddrill assembly having selective extendable and retractable relativelymovable portions; initiating anchoring of said drill assembly betweenthe roof and floor surfaces of said underground passageway by extendingsaid relatively movable portions into engagement with said roof andfloor surfaces, respectively; completing said anchoring andsubstantially simultaneously therewith unclamping said drill assemblyfrom said support means; drilling at least one roof bolt hole above saidroof surface; clamping said drill assembly to said support means withlimited motion only in said given direction being maintained betweensaid drill assembly and said mobile means; and retracting saidrelatively movable means until said relatively movable means are freefrom said roof and floor surfaces.
 2. A method as specified in claim 1including the additional step of: subsequent to said retracting saidrelatively movable means, moving said drill assembly in said givendirection to selectively reposition said drill assembly with respect tosaid mobile means.
 3. A method as specified in claim 1 including theadditional steps of: during said releasing said drill assembly from saidsupport means, locating said mobile means to maintain limited relativelinear and transverse motions between said drill assembly and saidsupport means; and subsequent to said retracting said relatively movablemeans, moving said drill assembly in said given direction to selectivelyreposition said drill assembly with respect to said mobile means.
 4. Amethod as specified in claim 3 including the additional step of: duringsaid drilling maintaining said limited relative linear and transversemotions.
 5. A method as specified in claim 4 wherein said drill assemblyadditionally includes selectively extendable and retractable relativelymovable timber jack means and comprising the additional steps of:subsequent to said anchoring of said drill assembly and prior to saiddrilling, anchoring a timber roof support intermediate said roof supportand said timber jack means by extending jack means into engagement withsaid timber roof support and continuing said extending until said timberroof support engages said roof surface and said anchoring is complete;and prior to said moving said drill assembly, retracting said timberjack means until said timber jack means are free from said timber roofsupport.
 6. A method as specified in claim 5 wherein said drilling is insaid roof surface above said timber jack support and including theadditional step of; subsequent to said drilling and prior to saidretracting said timber assembly, securing said timber jack support saidroof surface by roof anchorIng means extending between said timerassembly and said roof bolt hole.
 7. A method as specified in claim 4including the additional step of: prior to said moving said drillassembly, securing a roof anchoring means in said roof bolt hole.
 8. Adrilling apparatus comprising: an elongated mobile assembly; at leastone drill assembly; cooperable means carried by said drill assembly andsaid mobile assembly for releasably securing said drill assembly to saidmobile assembly; said cooperable means including an elongated portioncarried by one of said assemblies and a clamping portion carried by theother of said assemblies with said clamping portion being selectivelyvertically movable into a clamped and unclamped relationship with saidsupport portion; said drill assembly having selectively extendable andretractable anchoring means relatively movable along a vertical axis;and control means carried by at least one said assemblies forselectively actuating said cooperable means and said anchoring means. 9.A drilling apparatus as specified in claim 8 wherein said drill assemblyadditionally comprises a selectively extensible roof support timberjack.
 10. A drilling apparatus as specified in claim 8 with saidclamping portion being locatable with respect to said support portion toprovide limited relative linear and transverse motions between saidclamping portion and said support portion when said clamping portion isin unclamped relationship with said support portion; and limitedrelative motion only in the elongated direction of said mobile assemblybetween the clamping portion and said support portion when said clampingportion is in clamped relationship with said support portion.
 11. Adrilling apparatus as specified in claim 10 with one of said portionshaving a pair of continuous vertically concaved oppositely facingsurfaces which interfit with and at least partially encompass a pair ofcontinuous vertically convex surfaces on the other of said portions. 12.A drilling apparatus as specified in claim 11 wherein said supportportion is fixedly secured to said mobile assembly and said clampingportion is pivotally secured to said drill assembly.
 13. A drillingapparatus as specified in claim 12 wherein said concave surfaces aresurfaces of said clamping portion and said convex surfaces are surfacesof said support portion.
 14. A drilling apparatus as specified in claim8 additionally including positioning means carried by at least one ofsaid assemblies for selectively positioning said drill assembly withrespect to said mobile assembly.
 15. A drilling apparatus as specifiedin claim 14 additionally including control means carried by at least oneof said assemblies for selectively actuating said positioning means.